In recent years, color printing or complex printing has rapidly increased in photochemical printing processes. Therefore, demand for the improvement and stability of the quality of the silver halide photographic light-sensitive material, which is an intermediate medium for printing (hereinafter referred to a printing light-sensitive material) increases year by year.
Heretofore, to achieve high quality of a general light-sensitive material for printing, it is adapted with so-called "lith development". However, in "lith development" it is mechanically impossible to comprise in a developer solution a preservative, a sulfite in a high concentration and therefore, it is well known in the art that the stability of such developer is very poor.
As a technique to overcome the instability of lith development and obtain a high contrast image as obtained in lith development, a method using a hydrazine compound is disclosed in Japanese Patent O.P.I. Publication Nos. 53-16623 (1978) , 53-20921 (1978) , 53-20922 (1978) , 53-49429 (1978) , 53-66731 (1978), 53-66732 (1978), 53-77616 (1978), 53-84714 (1978), 53-137133 (1978), 54-37732 (1979), 54-40629 (1979), 55-52050 (1980) , 55-90940 (1980) , 56-67843 (1981) and 6-106244(1981). To obtain a high contrast image in the processing method using these hydrazine compounds, pH of the developing solution containing the compounds or the pH of the developing solution of the photographic light-sensitive material comprising the compounds had to be relatively high. As a result, there was a problem that the effective lifetime of the developing solution tended to be shortened.
To overcome this problem, Japanese Patent O.P.I. Publication Nos.63-29751 (1988), 1-179939 (1989) and 1-179940 (1989) and U.S. Pat. No.4,975,354 disclose a silver halide light-sensitive photographic material which comprises a hydrazine derivative and a nucleation accelerating agent, by which a high contrast photographic image can be obtained with a developing solution of relatively low pH. With the use of the contrast increasing agents, however, there was still a tendency that a lot of black spots, which are minute fog, occur. As means for decreasing the black spots, a technique of incorporating an acid polymer latex in silver halide light-sensitive photographic material is disclosed in Japanese Patent O.P.I. Publications Nos. 61-228437 (1986) and 4-106542 (1992), however, in order to obtain a high contrast image by this method using a developer of relatively low pH, it was necessary that an amino compound be added to the developing solution as a development accelerating agent. The amino compound added to the developer often has an extremely unpleasant smell. Moreover, it has an additional defect that the developing ability of the developing solution easily fluctuates due to its volatile nature. Furthermore, in order to stabilize dispersion of the latex in water, it is necessary to add a specific surfactant, however, this method limits the kinds of emulsions used and there has not yet been found a surfactant that does not give adverse influence on fog, sensitivity and development properties.